Abstracts ASN Report 2019

approved organisations is carried out at the different stages of the design and manufacture of the NPE. It takes the form of an examination of the technical documentation of each equipment item and inspections in the workshops of the manufacturers, as ŊĸĿĿ Ĵņ ĴŇ ŇĻĸļŅ ņňŃŃĿļĸŅņ ĴŁķ ņňĵĶłŁŇŅĴĶŇłŅņє ļʼnĸ ļŁņŃĸĶŇļłŁ organisations are currently approved by ASN to assess NPE ĶłŀŃĿļĴŁĶĸѓ ŃĴʼnĸׇ ё ņĴŃё ňŅĸĴň ĸŅļŇĴņ ŋŃĿłļŇĴŇļłŁё ļŁŬłŇŇĸ ŁŇĸŅŁĴŇļłŁĴĿ ĴŁķ ŇĻĸ ļŁņŃĸĶŇļłŁ łŅĺĴŁļņĴŇļłŁ łĹ users. Ł ӅӃӄӌё ŇĻĸ ĴŃŃŅłʼnĸķ łŅĺĴŁļņĴŇļłŁņ ĶĴŅŅļĸķ łňŇ ӅёӅӄӌׇļŁņŃĸĶŇļłŁņ on NPE design and manufacture for the NPE intended for the ĿĴŀĴŁʼnļĿĿĸ ĴŁķ ӆёӈӃӄׇļŁņŃĸĶŇļłŁņ ĹłŅ ŇĻĸ ŅĸŃĿĴĶĸŀĸŁŇ intended for the NPP reactors in operation. These inspections are performed under ASN supervision. א ِ א ِ א ɀɀƺɀɀȅƺȇɎ Ȓǔ Ɏǝƺ ƳƺɀǣǕȇ ƏȇƳ ȅƏȇɖǔƏƬɎɖȸƺ Ȓǔ z¨0 • ƬɎǣȒȇɀ ǔȒƬɖɀƺƳ Ȓȇ ƳƺɮǣƏɎǣȒȇɀ ƏȇƳ ǣȸȸƺǕɖǼƏȸǣɎǣƺɀ ƳƺɎƺƬɎƺƳ ǣȇ Ɏǝƺ ȅƏȇɖǔƏƬɎɖȸǣȇǕ ȵǼƏȇɎɀ ѡņ ĴĶŇļłŁņ ļŁ ӅӃӄӌׇŇł Ĵņņĸņņ ĸńňļŃŀĸŁŇ ĶłŀŃĿļĴŁĶĸ ĴŁķ ĶĻĸĶľ its manufacturing were particularly focused on the examination of the deviations detected, in particular those which had affected the stress-relieving heat treatment of the connecting welds for ŅĸŃĿĴĶĸŀĸŁŇ ĶłŀŃłŁĸŁŇņё ŃŅłķňĶĸķ ĴŇ ŇĻĸ ŅĴŀĴŇłŀĸ ĴļŁŇі Marcel plant. ņ ļŁ ӅӃӄӋё ŇĻĸ ŌĸĴŅ ӅӃӄӌׇŊĴņ ĴĿņł ŀĴŅľĸķ ĵŌ ŇĻĸ ĹłĿĿłŊіňŃ Ňł ŇĻĸ ĻĴŁķĿļŁĺ łĹ ŇĻĸ ļŅŅĸĺňĿĴŅļŇļĸņ ķĸŇĸĶŇĸķ ļŁ ӅӃӄӉׇļŁ ņĸʼnĸŅĴĿ ŀĴŁňĹĴĶŇňŅļŁĺ ŃĿĴŁŇņё ļŁ ŃĴŅŇļĶňĿĴŅ ļŁ ŅĴŀĴŇłŀĸѡņ ŅĸňņłŇ łŅĺĸ ŃĿĴŁŇє Ł ӅӃӄӌё ĹłĶňņĸķ łŁ ŇĻĸ łŁĸ ĻĴŁķ łŁ ĶłŁŇļŁňļŁĺ to examine the impact of these irregularities on equipment compliance and, on the other, on continuing to implement the ļŀŃŅłʼnĸŀĸŁŇ ŃĿĴŁ ĹłŅ ŇĻĸ ŅĸňņłŇ łŅĺĸ ŃĿĴŁŇё ŊĻļĶĻ ŁłŇĴĵĿŌ includes reinforcing the safety culture, improved management of the industrial tools and consolidation of technical skills. ŅŅĸĺňĿĴŅļŇļĸņ ŊĸŅĸ ĴĿņł ŅĸŃłŅŇĸķ ĴŇ ŇĻĸ ĸŁķ łĹ ӅӃӄӋׇĵŌ ŇĻĸ ŅĴŀĴŇłŀĸ ņňŃŃĿļĸŅ ňĵĸŅŇ հ ňʼnĴĿє Ļĸņĸ ļŅŅĸĺňĿĴŅļŇļĸņ ĴĹĹĸĶŇ numerous past or present equipment manufacturing operations. The investigations carried out have not yet identified any consequences for the safety of the facilities. Together with the organisations to which it gives a mandate, ASN is examining the ĴĶŇļłŁņ łĹ ŅĴŀĴŇłŀĸ ĴŁķ Ĵļŀĸķ ĴŇ ķĸĹļŁļŁĺ ŇĻĸ ņĶłŃĸ ĴŁķ impact of these irregularities. At the same time, and on the basis of these findings, ASN ensures that the manufacturers and licensees develop an organisation and means for detection of such practices within their own structures, so that the necessary steps can be taken to more effectively rule out the risks of fraud. It is also adapting its oversight practices, notably by means of a greater number of unscheduled inspections. • «ƺǣȇǔȒȸƬǣȇǕ ǴɖɀɎǣǔǣƬƏɎǣȒȇ Ȓǔ Ɏǝƺ ƳƺɀǣǕȇ Ȓǔ z¨0 ASN has regularly observed that the justifications and demonstrations provided by the manufacturers with regard to the regulations applicable to NPE, notably in terms of the satisfactory design of this equipment, are unsatisfactory. The industrial firms, ĴŁķ ŅĴŀĴŇłŀĸ ļŁ ŃĴŅŇļĶňĿĴŅё ŇĻĸŅĸĹłŅĸ Ňłłľ ĹňŁķĴŀĸŁŇĴĿ ŀĸĴņňŅĸņ Ĵņ łĹ ŇĻĸ ĹļŅņŇ ĻĴĿĹ łĹ ӅӃӄӈׇŇł ĶĻĴŁĺĸ ŇĻĸļŅ ŃŅĴĶŇļĶĸņ and bring them into line with the regulatory requirements. ASN monitored these actions, most of which were carried out within ŇĻĸ ĹŅĴŀĸŊłŅľ łĹ ŇĻĸ ŅĸŁĶĻ ņņłĶļĴŇļłŁ ĹłŅ ĸņļĺŁё łŁņŇŅňĶŇļłŁ ĴŁķ łŁļŇłŅļŁĺ ňĿĸņ Ҏ ҏ ĴŁķ ļŁʼnłĿʼnĸķ ŇĻĸ majority of the profession. ASN considers this approach to be a positive one and, for most of the problems identified in 2015, ĶłŁņļķĸŅņ ŇĻĴŇ ŇĻĸ ĺňļķĸņ ĴŁķ ŀĸŇĻłķņ ŃňĵĿļņĻĸķ ĴŅĸ appropriate. This approach will be repeated in the coming years so that the profession continues to make progress on certain topics and in order to learn the lessons from the initial applications of the guides and methods created. א ِ א ِ ב xȒȇǣɎȒȸǣȇǕ Ɏǝƺ ȒȵƺȸƏɎǣȒȇ Ȓǔ ¨ȸƺɀɀɖȸƺ 0ȷɖǣȵȅƺȇɎ The reactor Main Primary and Secondary Systems (CPP and CSP) operate at high temperature and high pressure and contribute to the containment of the radioactive substances, to cooling and to controlling reactivity. The monitoring of the operation of these systems is regulated ĵŌ ŇĻĸ ŅķĸŅ łĹ ӄӃׇ łʼnĸŀĵĸŅ ӄӌӌӌׇŅĸĿĴŇļʼnĸ Ňł ŇĻĸ ŀłŁļŇłŅļŁĺ łĹ operation of the main primary system and the main secondary ņŌņŇĸŀņ łĹ ŁňĶĿĸĴŅ ŃŅĸņņňŅļōĸķ ŊĴŇĸŅ ŅĸĴĶŇłŅņє Ļĸņĸ ņŌņŇĸŀņ are thus the subject of monitoring and periodic maintenance by є Ļļņ ŀłŁļŇłŅļŁĺ ļņ ļŇņĸĿĹ ĶĻĸĶľĸķ ĵŌ є These systems are subject to periodic re-qualification every ten years, which comprises a complete inspection of the systems involving non-destructive examinations, pressurised hydrotesting and verification of the good condition and good operation of the over-pressure protection accessories. • zǣƬǸƺǼ ٮ ƫƏɀƺƳ ƏǼǼȒɵ ɿȒȇƺɀ Several parts of PWRs are made of nickel-based alloy. This type of alloy is chosen for its resistance to generalised or pitting corrosion. However, in the reactor operating conditions, one of the alloys chosen, Inconel 600, has proven to be susceptible to stress corrosion. This particular phenomenon occurs in the presence of significant mechanical stresses. It can lead to the appearance of cracks, as observed on certain SG tubes in the ĸĴŅĿŌ ӄӌӋӃņ łŅё ŀłŅĸ ŅĸĶĸŁŇĿŌ ļŁ ӅӃӄӄё łŁ Ĵ ʼnĸņņĸĿ ĵłŇŇłŀ ĻĸĴķ ŃĸŁĸŇŅĴŇļłŁ ļŁ ŅĴʼnĸĿļŁĸņ ŅĸĴĶŇłŅ ӄׇĴŁķ ļŁ ӅӃӄӉׇłŁ Ĵ ʼnĸņņĸĿ bottom head penetration in Cattenom NPP reactor 3. Ļĸņĸ ĶŅĴĶľņ ŅĸńňļŅĸ ŇĻĴŇ ŇĻĸ ĿļĶĸŁņĸĸ ŅĸŃĴļŅ ŇĻĸ ōłŁĸņ ĶłŁĶĸŅŁĸķ or isolate the part of the system concerned. Ň ŇĻĸ ŅĸńňĸņŇ łĹ ё ĴķłŃŇĸķ ĴŁ łʼnĸŅĴĿĿ ĴŃŃŅłĴĶĻ Ňł ŀłŁļŇłŅļŁĺ ĴŁķ ŀĴļŁŇĸŁĴŁĶĸ ĹłŅ ŇĻĸ ōłŁĸņ ĶłŁĶĸŅŁĸķє ĸʼnĸŅĴĿ ōłŁĸņ łĹ ŇĻĸ ŀĴļŁ ŃŅļŀĴŅŌ ņŌņŇĸŀ ŀĴķĸ łĹ ŁĶłŁĸĿ ӉӃӃׇĴĿĿłŌ ĴŅĸ ŇĻňņ ņňĵĽĸĶŇ Ňł ņŃĸĶļĹļĶ ŀłŁļŇłŅļŁĺє łŅ ĸĴĶĻ łĹ ŇĻĸŀё ŇĻĸ in-service monitoring programme, defined and updated annually by the licensee, is submitted to ASN, which checks that the ŃĸŅĹłŅŀĴŁĶĸ ĴŁķ ĹŅĸńňĸŁĶŌ łĹ ŇĻĸ ĶĻĸĶľņ ĶĴŅŅļĸķ łňŇ ĵŌ are satisfactory and able to detect the deteriorations in question. • Áǝƺ ɀɎȸƺȇǕɎǝ Ȓǔ ȸƺƏƬɎȒȸ ȵȸƺɀɀɖȸƺ ɮƺɀɀƺǼɀ The reactor pressure vessel is an essential component of a PWR ĴŁķ ĶłŁŇĴļŁņ ŇĻĸ ŅĸĴĶŇłŅ ĶłŅĸ ĴŁķ ļŇņ ļŁņŇŅňŀĸŁŇĴŇļłŁє łŅ ŇĻĸ ӌӃӃ ĸ ŅĸĴĶŇłŅņё ŇĻĸ ʼnĸņņĸĿ ļņ ӄӇŀ ĻļĺĻё Ӈŀ ļŁ ķļĴŀĸŇĸŅё ӅӃĶŀ ŇĻļĶľ ĴŁķ ŊĸļĺĻņ ӆӆӃׇŇłŁŁĸņє łŅ ŇĻĸ ё ĶňŅŅĸŁŇĿŌ ňŁķĸŅ ³z ǣȇɀȵƺƬɎǣȒȇ ǣȇ Ɏǝƺ ǼƏɵƏǣɀ z¨¨ ٫ xƺƏȇɀ ƳƺȵǼȒɵƺƳ ɎȒ ȅƏȇƏǕƺ Ɏǝƺ ȸǣɀǸ of foreign objects in the systems ASN Report on the state of nuclear safety and radiation protection in France in 2019 283 ׏׎ ٲ THE EDF NUCLEAR POWER PLANTS 10